Abstract

Studies of the potential contamination of currency with parasites have not been given the interest it deserves. A lot has been done on microbial contamination of currency with viruses, bacteria and fungi. We therefore investigated the contamination of Nigerian currency with the eggs and cysts of parasites in Ojo local government, Lagos State, Nigeria. A Total of 100 samples of Nigerian currency (Naira) consisting of 20 pieces of lower denomination (N5-N10) were examined microscopically using the rinse method. The notes were grouped into dirty and dirty/mutilated. 59% were contaminated with the eggs and cysts of parasites. 18 (64.2%) of the dirty notes were contaminated while 41 (54.9%) of the dirty/mutilated notes were contaminated. Eggs and Cysts of five parasites were recovered. Eggs of Ascaris lumbricoides 38.9%, Hookworm 25.4%, Enterobius vermicularis 3.38%, Trichurus trichiura 10.1% and Cyst of Entamoeba histolytica 8.4%. There were also mixed infections (13.5%). Five Naira and Ten Naira notes were the most contaminated (23.7% each) while the least contaminated was N100 (15.2%). Citizens should be educated on ways of handling money through personal hygiene by not abusing, mishandling or mutilating the Naira. People should be encouraged to keep their money in wallets or purses and not on dirty surfaces. The Central bank of Nigeria should put in place and maintain a retrieval system which will ensure that mutilated notes do not remain in circulation for too long.

Keywords

Cyst, Eggs, Parasites, Currency, Naira notes, Denominations

Introduction

In ancient times, people did not need money. They practiced
trade by barter. In the early 1800 s and 1900 s Scientist began
to theorize that transmission of money was associated with
the transmission of diseases (Alemu, 2014). A paper currency
note is widely exchanged for goods and services worldwide
and was first developed in China (Prasai et al., 2008). Money
is used as a medium for exchange of goods and services,
settlement of debts and for deferred payments in economic
activities (Beg and Fisher, 1997). Money is the most widely
used and sought after service on planet earth with the potential
of changing from one user to the other so could fuel disease
spread and a risk to public health (Neel, 2012). An individual
living in unhygienic condition will therefore contaminate
the notes and these acts as a vehicle to the next user (Ogba,
2007). Currency is handled by large number of people under
a variety of personal and environmental conditions thus
increasing the possibility of acting as environmental vehicle
for transmission of potential pathogenic organisms. Paper
currency provides a large surface area as breeding ground
for pathogens (Michael, 2002). The contamination of notes
could be from several sources i.e. the atmosphere, storage,
usage, handling or production (Matur et al., 2008). Daily
transactions have made money pass through many hands. The
Naira (N) is the legal tender in Nigeria. Lower denominations
of currency are exchanged more than higher denominations
because they are frequently handled in petty daily transactions, more widespread and exchangeable between
lower economic classes. Higher denominations show lesser
contamination (Matur et al., 2008, Awodi et al., 2000, Oyero
and Emikpe, 2007, Ekejindu et al., 2005, Yazah et al., 2012,
Emikpe and Oyero, 2007). In this study lower denominations
were collected for analysis. Age of the note and material used
influences the degree of contamination. Paper notes have been
shown to be more contaminated than polymer notes (Oyero
and Emikpe, 2007). The Nigerian Naira note is a mixture of
75% Cotton and 25% linen (Brady and Kelly, 2000).

A lot of studies have been carried out on microbial
contamination of currency with viruses, bacteria and fungi
(Alemu, 2014, Brady and Kelly, 2000, Umeh et al., 2007,
Ayandele and Adeniyi, 2011, Yakubu et al., 2014, Awe et al.,
2010, Orukotan and Yahaya, 2011). Accumulated data over
the last 20 years on microbial status and survival of pathogens
on currency notes indicated that they represent a potential
cause of food borne diseases (Alemu, 2014). Microbes are
ubiquitous and their ability to contaminate objects is more
prevalent when compared to parasites (Jolaosho, 1991).

Parasites with direct life cycles do not need an intermediate
host to infect a new host so can be acquired by direct ingestion
of eggs or cyst and this can be from contaminated surfaces
like banknotes. Parasites that have been observed to be able
to contaminate naira notes are mainly of feacal origin (Awodi et al., 2000).

Currency notes with parasites have been detected in
Nigeria by several scientists. Parasites that have been isolated
from currency in Nigeria are eggs of worms like Ascaris
lumbricoides, Hookworms, Trichurus trichiura, Enterobius
vermicularis, Taenia, Toxocara, Hymenoplepsis nana and dimunuta. Cysts of protozoans like Entamoeba histolytica,
Giardia lamblia, Balantidium coli and Isospora have been
recovered so also flagellates, lice and mites (Matur et al.,
2008, Awodi et al., 2000 , Ekejindu et al., 2005, Matur et
al., 2010, Orji et al., 2013, Uneke and Ogbu, 2007). Even
Automated Teller machines (ATM) and currency counting
machines have been observed to be infected with pathogens
in Nigeria, presenting a risk to bankers and customers
(Enemuor et al., 2012).

The objectives of this present study is to investigate
the prevalence of parasites on Nigeria banknotes(lower
denominations) which of these denominations have the
highest and least contamination and what type of parasites
are found on the currency notes.

Materials and Methods

Study population

The study was conducted in Lagos State University (LASU),
Zoology Laboratory. LASU is in Ojo local Government
area of Lagos State, Nigeria. A total of 100 samples of
Nigerian currency notes consisting of 20 pieces each of
lower denominations (N5- N100) were collected from food
vendors, beggars, butchers, bus conductors, hawkers and
traders outside the LASU Ojo Campus and from Students
within the campus.

Collection of Naira notes

The Naira notes were collected aseptically with hand gloves
into a sterile polythene bag and were conveyed to the Zoology
Laboratory for parasitological examination and analysis.

Grouping of samples

The Currency notes were in various physical conditions
and were categorized as dirty or Dirty/mutilated (damaged,
soiled, and squeezed with tapes).

Laboratory examination

The rinse method of Matur et al., (2010) was used. The
working bench was swabbed with 70% ethanol. Each
Currency note was folded and inserted into a sterile bottle
and 10 ml of 0.85% sterile normal saline was dropped on
each of the currency notes using a 10 ml syringe. Each bottle was covered and shaken vigorously and left standing for 30
minutes and shaken all over again. The notes were removed
using a pair of sterile forceps and transferred to sterile
polythene bags. The content of each bottle was centrifuged
in a 15 ml centrifuge at 1500 revolutions per minute for 2
minutes. The resultant sediment was stirred with a clean
applicator stick and a drop was placed on a clean grease
free slide with a drop of Lugols iodine (5%) and examined
microscopically at x40 and x100 for the presence of parasite
eggs and cysts under a compound binocular microscope.

Identification of parasites eggs and cyst

Only viable eggs and cysts were identified. Entamoeba
histolytica cysts were identified by a four nuclei ovoid cyst
of 10-15 μm containing rod shaped chromatoid bodies. The
eggs of Ascaris were embryonated, oval with characteristics
warty or mammilated appearance and 50 by 40 μm. They
were brownish yellow and thick shelled with three layers.
The eggs of hookworm were characterized by roundish,
thin, transparent hyaline shells with blastomeres of between
2-8 cells (60 μm by 40 μm). Trichuris trichiura eggs were
characterized by barrel or lemon shaped appearance with
bipolar protuberances or opercular plugs (50 by 25 μm). Enterobius vermicularis eggs are small, translucent, sticky,
clumped together in hundreds which aided visibility with a
thick shell flattened on one side looking like a D shape, the
size ranges from 50-60 μm by 20-30 μm.

Results

Of the 100 samples of currency examined, 28% were dirty
while 72% were dirty/mutilated. Five Naira note was the
dirtiest (45%) while 100 naira was the most dirty/mutilated
(80%). Overall 59% of the notes were contaminated with the
eggs and cysts of parasites. Eighteen (64.2%) of the 28 dirty
notes were contaminated while among the 72 dirty/mutilated
notes 41 (54.9%) of them were contaminated with parasitic
agents (Table 1). Overall, Hundred naira notes were the least
contaminated with parasitic agents (15.2%) even though was
the most dirty/mutilated while five and ten naira notes were
the most contaminated (23.7%) each. The differences were
not statistically significant (P<0.05).

Denomination (Naira)

Number examined

Dirty notes N (%)

Number Contaminated N (%)

Very dirty mutilated notes N (%)

Number contaminated N (%)

Total Contaminated N (%).

5

20

9 (45)

4 (44.4)

11 (55)

10 (90)

14 (23.7)

10

20

5 (25)

4 (80)

15 (75)

10 (66.6)

14 (23.7)

20

20

5 (25)

4 (80)

15 (75)

6(40)

10 (16.9)

50

20

5 (25)

3 (60)

15 (75)

9 (60)

12 (20.3)

100

20

4 (20)

3 (75)

16 (80)

6 (37.5)

9 (15.2)

Total

100

28(28)

18 (64.9)

72 (72)

41 (54.9)

59 (59)

Table 1: Physical condition of the 100 Naira notes and Number contaminated.

Cysts and eggs of five parasites were recovered. Ascaris lumbricoides eggs 38.9%, Hookworm eggs 25.4%, Enterobius vermicularis eggs (3.38%), Trichuris trichiura eggs (10.1%) and Entamoeba cyst (8.4%) (Table 2). There
were mixed infections of Ascaris lumbricoides, hookworm
and Trichuris trichuira in five and ten naira notes. Twenty
naira notes had mixed infections with A. lumbriciodes and Entamoeba cyst, fifty naira had mixed infections of A.
lumbricoides, Hookworm and Entamoeba cyst but no mixed
infections were found on the 100 naira notes. A total of 8
notes had mixed infections (13.5%).

Discussion

Improper handwashing after using the toilet and ATM
machines, counting paper notes using saliva or contaminated
water, coughing and sneezing on hands when exchanging
money, placement or storage of notes on dirty surfaces as
socks, shoes, carpets or brassieres, placing of money in the
mouth and biting off corners of notes leads to contamination
of notes and are all potential risk. In Nigeria, the Naira notes
are abused by squeezing, stapling, cello taping and writing
on them. They are sprayed during ceremonies where they are
trampled upon as they fall aground. These currency notes,
hardly last for more than one year in Nigeria, owing to these
poor or negative handling practices (Obi, 1999). This study
confirms that the Nigerian money the Naira acts as vehicle to
contaminate the next user and makes for cross contamination
and easy transfer of pathogen such as parasites (Awodi et al.,
2000, Ekejindu et al., 2005 , Umeh et al., 2007).

The denomination of notes influence the level of
contamination as the N100 was the least contaminated. This is
in consonance with some studies where lower denominations
were more contaminated than higher ones (Matur et al.,
2008, Awodi et al., 2000, Oyero and Emikpe, 2007, Ekejindu et al., 2005, Yazah, 2012 ). This is also a reflection of the
present poor economic situation in Nigeria where the Naira is
highly devalued to the extent that higher denominations have
suddenly become readily unavailable at all level for daily
transaction. The Parasites observed in this study have also
been observed from the results of past studies (Matur et al.,
2008, Awodi et al., 2008, Ekejindu et al., 2005, Matur et al.,
(2010), Orji et al., 2013, Uneke and Ogbu, 2007 ). However,
the potential health hazard of dirty and dirty/mutilated notes
is obvious from this study. Mint and clean notes have been
reported as having no parasites (Uneke and Ogbu, 2007).

Ascaris lumbriciodes eggs occurred with the highest
frequency in this study because of the resilience of the eggs that
can withstand extremes of environmental conditions. The eggs
are warty and coated with mucopolyssacaride which renders
them adhesive to many surfaces. The eggs are very resistant to
adverse environmental conditions and most chemical agents
which enable the egg to remain viable for a long period.

Conclusion

The Central bank of Nigeria (CBN) embarked on a campaign
in 1991 to educate the populace on the proper handling of the
Naira which they explained was responsible for its short life
span (Obi, 1999, Oladele, 1999). More of these campaigns
are needed. The CBN should put in place a retrieval system
which will ensure that mutilated notes do not remain in
circulation for too long. Citizens should be educated to
improve on the way they handle money and be encouraged to
keep their money in wallets or purses to reduce contamination
of money. Regular deworming of children will reduce the
amount of eggs available for transmission.